Effect of ZnO nanoparticles on the Judd–Ofelt and radiative parameters of Sm³⁺ ions in sol–gel silica matrix

The trivalent samarium ions doped with different concentrations of ZnO NPs in silicate glasses were prepared by the sol–gel technique. The structural and optical properties were characterized by using X-ray diffraction, Fourier transform infrared, scanning electron microscope, transmission electron microscope, optical absorption, and photoluminescence measurements at room temperature respectively. The structural analysis from X-ray diffraction, scanning electron microscope, and transmission electron microscope results confirmed the hexagonal wurtzite ZnO structure of all the nanoparticle samples. The evaluation has been made for the dependence of various radiative parameters along with the Judd–Ofelt of Sm³⁺ on the concentration of ZnO NPs. The effective network changing the nature of ZnO NPs has been revealed by the high value of Ω₂ obtained in this system matrix. In the current investigation, the silica matrix's emission transition ⁴G_5/2 → ⁶H_9/2 of Sm³⁺, which corresponds to the red color observed at 653 nm, demonstrated excellent radiative behavior compared to other commonly used glass hosts. These results suggest that Sm³⁺ ions doped with ZnO NPs in sol–gel silicate glasses can be more efficient luminescent materials in the field of lasers and optical devices in the visible region. CIE Chromaticity diagram observed that these coordinates fall in the bluish-purple to yellowish-orange region.